People with blood cancer are expected to be amongst those at increased risk of COVID-19 infection due to a weakened immune system from the effects of their cancer and the nature of the cancer treatment they receive.

Immunosuppression in blood cancer patients is also predicted to lead to more severe outcomes following infection. However, the present study found that even if patients were actively having intensive treatment for blood cancer that weakened their immune system, they usually recovered from COVID-19 as long as they were otherwise fit and well.

The study, published in the British Journal of Haematology, looked at 35 adult patients with blood cancer who had tested positive for COVID-19 and monitored them for a minimum of 14 days. At the end of the observation period, 60% of patients had recovered from COVID-19 infection.

The observations revealed that age was the most significantly associated factor with COVID-19 infection outcome, with almost all of the patients who died being aged 70 years or older at the time of COVID-19 diagnosis. Patients who died also had significantly more co-existing health conditions, such as hypertension, chronic kidney disease, or diabetes, than those who recovered from the virus.

Lead author of the study, Dr John Riches from Queen Mary University of London said: "Although this is a small and preliminary study, it is a first step in understanding the risk posed by COVID-19 to patients with blood cancers. At the current time, all patients with certain blood cancers are being advised to 'shield' to try to minimise the risk of getting the virus. However, this study suggests that the risk of COVID-19 to younger patients with few or no medical conditions aside from their blood cancer is less than the risk to older patients with lots of other medical conditions."

The data showed no correlation between blood cancer treatment and outcome following COVID-19 infection, and suggest that while patients with blood cancers have poorer outcomes than the general population after COVID-19, the majority still survive. While this is the largest study to date to examine the clinical outcome of COVID-19 infection in patients with blood cancer, the findings will need to be confirmed in large national and international registry studies.